Pedemy All toolsTap one score for each of the 12 signs. Each sign folds to its score, and the running total and estimated age update at once. All 12 give the final estimate.
This calculator scores the New Ballard Score (Ballard and colleagues, 1991), the standard bedside exam for estimating a newborn's gestational age. You tap one score for each of 12 signs: six neuromuscular (posture, square window, arm recoil, popliteal angle, scarf sign, heel to ear) and six physical (skin, lanugo, plantar surface, breast, eye and ear, genitals). Each sign shows an original Pedemy drawing of its categories. The running total and estimated age update with every tap, and the tool lists any sign still unscored.
Most signs score from −1 to 4. Popliteal angle and skin go up to 5, posture and arm recoil start at 0, and plantar surface and eye/ear go down to −2 for foot length under 40 mm and tightly fused eyelids. The total runs from −10 to 50 and maps to 20 to 44 weeks: every 5 points adds 2 weeks, so weeks = (2 × score + 120) ÷ 5. A score of 0 is 24 weeks, 20 is 32 weeks and 40 is 40 weeks. The estimate is reported as plus or minus 2 weeks.
In the 1991 validation of 578 infants, the score agreed with confirmed dates with a mean difference of 0.15 weeks. For infants under 26 weeks it was most accurate when done within 12 hours of birth (97% within 2 weeks). For more mature infants it stayed valid up to 96 hours. When reliable dates or a first-trimester ultrasound exist, use them first (ACOG 2017). Then plot birth weight on a growth chart for the age to classify the baby as SGA, AGA or LGA.
Add the 12 sign scores for a total from −10 to 50. Each 5 points adds 2 weeks, starting at 20 weeks for −10. So weeks = (2 × score + 120) ÷ 5: a score of 0 is 24 weeks, 20 is 32 weeks, 35 is 38 weeks and 50 is 44 weeks. The estimate is about ± 2 weeks.
Within the first 96 hours of life. For babies under about 26 weeks, the original study found it most accurate when done within 12 hours of birth. For more mature babies, accuracy held steady up to 96 hours.
The 1991 update added scores for extremely premature babies. A foot under 40 mm heel to toe scores −2 and 40–50 mm scores −1. Tightly fused eyelids score −2 and loosely fused lids −1.
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